On the second day of Ella Mildon’s 620-mile journey on horseback across the steppes of wild Mongolia, she got into trouble. Her sure-footed, semi-wild stallion had sunk down chest-deep into a muddy bog.

“The truth is, you can’t see sometimes when the marshes are going to give out beneath you,” she said, recounting the episode. But after some struggling, the horse was able to free itself.

Mildon, 23, a longtime island 4-H Rock Riders club member who now lives in Clallam County and has been riding horses for years, recently completed the Mongol Derby, a treacherous race across great plains, mountain paths and forestland held over 10 days last month. Competitors follow the same message delivery routes traced by Ghengis Khan more than 800 years ago, stopping every 25 miles at designated stations, called Urtuus, so they can exchange their horse.

Before riders arrive in Mongolia and embark on the derby, they must train extensively and be physically and mentally fit enough to be cleared by the medical staff. Once they start riding, they have to push themselves to their limits. All hours of the day are spent riding, sometimes through wind and rain, largely in solitude across vast, empty stretches of wilderness. At night, riders have to find a place to stay, either with local families or by making camp, and be able to care for themselves and their horses.

Mildon said she focused on building endurance, riding her bicycle to develop her muscle and core strength. But weeks after the race, she said her knees haven’t recovered from the constant shock absorption and from having to counteract the motions of the horses she rode from sunrise to sunset.

The group that puts on the annual race, The Adventurists, asks each rider participating in the derby to raise money for Cool Earth, a charity that works with indigenous communities to combat rainforest deforestation. The bar to enter the derby is high: only riders with proven experience on horseback are accepted to enter the competition. The entry fee is about $14,000 — cost-prohibitive for most. Mildon paid her fee in installments.

The Adventurists warn that the chance of serious injury or death is high out on the steppes.

“I don’t think it’s possible to do enough to get ready for something like that,” said Mildon, who uprooted her life to take on the challenge. “You have to quit your job and spend every day getting ready for something like that.”

Mildon founded her own horse training business and is a prominent eventer, where a horse and rider compete in a series of disciplines, including dressage, cross-country racing and show jumping. She was working at an eventing barn in Woodinville, riding up to eight horses a day, when she first learned about the Mongol Derby. It was something different than her average work-life and more rigorous than anything she had ever done before, which she said was reason enough to apply. She completed the online form again and again for five years until she was finally selected for an interview and had a spot on the roster.

This year saw 42 riders from all corners of the world set out for the derby. They were assisted in large part by Utruu families, who provided food, shelter, guidance and support. Local herders saw to the wellbeing of the horses, keeping them grazed and hydrated throughout the course, and specialized equine vets inspected each animal at rest.

Mildon spent her first day becoming acquainted with the horses, receiving veterinary briefings and learning how to communicate with the animals. They are used to the harsh conditions and a different way of life than the show horses Mildon is more familiar with. They are also quick thinkers — on the plains, she noted, they can really take off, but riders have to keep watch for marmot holes.

“If you land on them, sometimes they cave in,” Mildon said. “Most of the horses, they’ll either jump them or dodge them. They know what kind of ground is bad.”

Her mount that was submerged in the bog was small but fiercely capable, with a reputation that would intimidate novices. She said the vet who assessed the horse had strong words for the kind of animal that it is.

“She told me, ‘No matter what you do, do not get off of this horse. This horse is a bucker,’” Mildon said. She chose to ride it anyway, adding that she and the steed managed to get along well.

But on another leg of the derby, she added, something went wrong between her and her horse.

The pain in her knee had become nearly unbearable. A medic had wrapped it, but it made little difference. This horse, she said, “seemed like a level-headed guy” — perfect for what was supposed to be an easy trek to the next station.

Once on the saddle, Mildon couldn’t take it anymore and had to stretch out her bad knee.

“I didn’t know he would notice, but as soon as I got my foot out of the stirrup, he said, ‘No, screw you,’ and knocked me off onto the ground,” she said. Mildon watched the angry horse gallop away.

A handler managed to retrieve the horse, but he had made up his mind about Mildon, and as soon as she climbed back on, he started to buck.

“I tried every trick in the book, but he would not stop, and now this whole rodeo is going on,” she said.

Not long after, she hit the ground again. It knocked the wind out of her — she said she was barely able to find the breath to say she was alright. She took a ride the rest of the way.

Mildon did not finish the derby with an official time — the horse that bucked her ultimately knocked her out of the running, but she said it didn’t matter. She was able to spend more time getting to know the friendly Mongolian people, many of whom are nomadic, traveling with goats, sheep and other livestock.

“I learned so much about Mongolia and so much about the people there. … It was really nice just to stay in such a pleasant country,” Mildon said. “When you lose a horse, the people will come out of the hills and catch it for you. Sometimes you feel kind of like, ‘Shoot, I wish you hadn’t been watching that.’”

Islander Bunny Hatcher is a leader of the island’s 4-H Rock Riders club. She said that when Mildon was a young club member, she often kept the crowds and her fellow riders wide-eyed.

“She was an amazing rider, a gutsy rider. She would pretty much get on anything and give it a spin,” said Hatcher, recalling one instance where Mildon successfully wrangled an out-of-control horse to safety, radiating calm. “That’s absolutely Ella.”

As new members come and go from the island’s 4-H club, Hatcher said that Mildon continues to set a strong example for all aspiring horseback riders to follow.

“We have a saying: We have old riders, and we have bold riders, but we don’t have old, bold riders. It’s nice to see her keeping up.”